According to the present invention, techniques for digital mapping are provided. In particular, the present invention provides methods, devices, and systems for displaying selected features on the chart of a body of water and associated areas. More particularly, the present invention provides systems, methods, codes, and devices for selectively highlighting one depth or one or more ranges of contiguous depths on the chart of a body of water or varying the depth values for contour lines on such chart on the display of a Global Positioning System (GPS) or coupled to a device of the GPS. As an example, ProMap Technologies, Inc., dba; LakeMasterLake Maps has developed a Chart Library and API that allows GPS manufacturers to embed the API into their OS and thus display proprietary LakeMaster Digital Charts. These LakeMaster Digital Charts reside on a secure SD media card in a format compatible through the API with various GPS Devices. Of course, there can be other variations, modifications, and alternatives.
GPS and underwater sounding devices (SONAR) have made access to navigational charts more readily availability to the angler. Newer charts created with modern technology reach accuracies of within less than one foot for location and depth. Such accuracies allow the creating of highly accurate marine charts capable of depicting the lake bottom in a manner imitating photographic imagery. GPS devices standing alone or coupled with SONAR units have opened a whole new dimension of information available to mariners, anglers and recreational boaters. Data collected during the mapping process has expanded to include not only bottom depth but bottom composition, hardness light penetration, weed growth, periodic tidal or random water level changes together with currents to name some examples.
Although highly successful, GPS devices alone or with SONAR units still have limitations. As an example, such devices are often cumbersome and lack easy to use functions. Without accurate charts that provide easy access to the information they can provide, GPS devices can do little more than allow you to find a previously known point. With accurate charts and user friendly ways to sort and present the information they contain, GPS devices can open entire new worlds of information. Conventional GPS display presentations tend to be static. That is to say, they present information in the same fashion as traditional paper maps. There is no ability to highlight particular features or change the way the chart is presented. Moreover, the conventional GPS device fails to provide ways to modify and display chart data to reflect real time conditions encountered by the user. Additionally, the conventional units do not provide a user with the ability to modify the GPS chart display to reflect potential changes in conditions such as water depth that have or may occur on the water body since the chart was produced.
From the above, it is seen that techniques for improving how GPS and SONAR units present their data are highly desirable.